Revealing mistake: After the jailbreak, a number of reaction shots for which the shot background is the villagers in the speeding wagon, not only do they not "bounce" with the wagon, they are not even animated.
Revealing mistake: When Barbara Windsor is fighting Margaret Nolan in the Hotel Lobby, they jump onto a sofa and it falls backwards. If you look carefully, the lady seated on the sofa can be seen helping it fall backwards with her foot.
Revealing mistake: At one point John is complaining about the Beach Boys playing on his car radio, he reaches to the center console and motions turning the radio off. In a few other shots though, we see that the car appears to have no radio at all, the center console seems to have a large tachometer and speedometer there, but that's all.